Saw sharpener



J. M c EWA N SAW SHARPENER Dec. 26, 1950 3 Sheets-Sheet 1 Filed May 27, 1949 4 wws/v 70R annex McEWA/v ATTORNEY Dec. 26, 1950 J. MOEWAN 2,535,439

SAW SHARPENER Filed May 2'7, 1949 5 Sheets-Sheet 2 lA/Vl/VTGR JflMEf MC EWA/Y nrromvsy J. M EWAN SAW SHARPENER Dec. 26, 1950 3 Sheets-Sheet 3 Filed May 27, 1949 FIG. 6'-

INVENTOR JAMEJ Mc awn/v W ZZQ Arron/v6) Patented Dec. 26, 1950 UNITED STATES ATENT OFFICE SAW 'SHARPENER James McEwan, San Jose, Calif.

Application May 27, 1949, Serial No. 95,729

. 11 Claims. "1

"The :present invention relates to :saw sharpeners for use with hand saws and the like and is concerned more particularly withthe provision of an improved sharpener of this kind which provides 'for'ready .and accurate adjustment of the saw iii-desired angular relations with respect to the. grinding wheel or other sharpening device. The sharpener also provides for easy adjustment oi :the feedzmechanismaof the sharpenerfor'selectionsof the proper sfeedincrements ,or steps with reference "to the number of teeth per inch of the saw'so that this adjustment can be made readily and accurately.

"The above :and other objectsof the invention will abe apparent from the following description of a .preferred embodiment of the invention as illustrated "in the accompanying drawings, in which:

:Figure .liis a perspective view of the saw sharpener.

Figure 2 is an end elevational view of the sharpener.

u-F'igure3 isa :view t-akenin the samev direction as Figure 2 rbutshowing :the parts in. section and inadifferentadjusted position with reference to the grinding wheel. The plane of .the sectional portion :of Figure .3 .is indicated :by the line J 3-3 in :Eigure 5.

Figure 4 is a plan view of the saw holder of the'saw sharpener.

zliigureifi isan elevational view of the adjusting or setting means forselecting the steps of movement of :the saw with :reference to the wheel in accordance with the number of points per inch in aparticular saw.

Figure 6 is an'elevational view, partly in section, of one side of the adjustable saw holder.

/" Figure'7 is a'fragmentary sectional view taken asindicated bythe line 1! in Figure 5.

Ingenera1=the -saw sharpener disclosed'herein provides for easy and quick installation of the saw in the sharpener, for accurate and --quick alignment of the saw with respect to the step-bystep'f-eed mechanism of the sharpener, and for easyand accurate-rotative adjustment of the saw with respect to the grinding-wheel, all such adjustments being made with reference to the point of cutting of the grinding wheel with reference to'the saw. 7

"Referring to "Figure'l, the sharpener includes a mounting post Ii! carrying at its upper end a support bracket 5 l on which a grinding wheel I2 is mounted for vertical adjusting movement. The bracket ii also provides a mounting for a drive motor it for the wheel it. The mounting and adjustment of the grinding wheel [2 may be in accordance with the disclosure of my copending application Serial No. 779,001, filed October 10, 1947, for Saw Sharpener.

The support post or standard it has adjustably clamped thereon a mounting bracket IE on which a horizontal mounting plate ll is rotatively mounted about a vertical axis passing through the grinding wheel I? at a diameter thereof so that this axis passes through the point G of gr nding engagement of the wheel with respect toa saw Hi held in the saw sharpener as later described. The adjustment of the plate ll with respect to its mounting bracket i6 is maintained by means of suitable clamps i8, and the angularly adjusted position of the plate can be read on graduations iii by means of a pointer 20. The plate ll has a vertical flange 2i on which a cam support plate 22 grooved to fit over the flange 2| is secured by means of one or more clamping screws 23. The vertical guide plate 22 has an arcuate upper guide surface 22a having angular graduations thereon and the center of this arouate surlace coincides with the point of grinding of the wheel lZ-on a saw. Mounted on the flange 2| in cooperativerelation-with the vertical plate 22 is a second mounting bracket 28 (Figures 1 and 3) Which'embra-ces both the-flange 2i and theplate 22. The-bracketjiii is releasably clamped in position by means of a clamping screw 25. By adjustment of the plate 22 between the mounting bracket 25 and the flange iii the angular position 0f;,.the bracket iican be varied as stated above.

The bracket 25 (Figures '1, 2 and 3) has a central transverse grooveii therein andrespective concave end ribs .28 on which a support or frame member-2i? .of the saw holder is mounted with the respective arcuate bottom surfaces 3i thereof engaged with the ribs 28. A tongue 35 on the framemember 'iiiiextends into the groove =27 to maintain the alignment of the parts. As stated above, the arcuate bottom surfaces iii of the member 29 seat on thearcuate surfaces of the ribs 32 so that the member 29 and the elements supported thereby including the saw It can be adjusted about an axis passing through the point G of grinding of the wheel i2. The desired angular adjustment can be selected by the graduations 33 on one of the ribs 28 and a corresponding index mark on the member 29. As seen in Figure 3, the angularly adjusted position of the frame member 29 on the bracket 26 is mantained by a clamping bolt extending through a central aperture in the bracket 26 and a slot 33 in the tongue so or" the member 29.

The member 29 is generally L-shaped, as seen in Figures 1, 2 and 3, and has respective side wall portions 3'5 in which a saw holder support element i! is pivotally mounted at 32. Respective springs 13 urge the support element 4! toward the member 29. The member 29 has a pair of grooved rolls '53 mounted on the upper end thereof while the element M carries a similar roll A? centrally spaced with respect to the rolls The rolls 36 and 4'! are engaged by respective side rails or ribs of a split saw holder or clamp 1 9 having respective clampin screws 5! at the ends thereof. Respective springs 52 are seated about the screws 5i and urge the two halves o'" the saw holder apart. A saw blade i is mountet in the saw holder it and thereafter the saw holder 49 is mounted in between the rolls 3% and 4? to carry the blade of the saw past the grinding wheel 52 in incremental fashion, as will now be described.

One portion of the saw holder or clamp as is provided with a rack 6i (Figures 1, 5 and 8) which meshes with a gear tra'n including an upper gear 52, an intermediate large idler gear 853, both journalled on the member 29, and a lower gear E i carried by a sleeve 66 (Figures 1 and 3). The sleeve as is journalled about a fixed shaft iii secured in the support member 29. The sleeve 55 carries a hand wheel 58 having a transverse strap at extending thereacross (Figures 3 and 5). The strap 69 carries a slidable bracket H (Figures 5 and '7) hav ng a spring-pressed pin i2 mounted therein and is adjustably clamped with respect to the transverse member 89 by a set screw 73.

The tapered end of the pin '52 is adapted to engage travel of the hand wheel as the pin l2 travels between adjacent holes of a selected series is transmitted to the sleeve 66 and through the gearing 6 3, 63 and 62, to the saw holder or clamp ii to efiect an exact increment of movement to the saw with respect to the grinding wheel i2.

The spacing of the holes 16 in a given series in a quadrant is determined with reference to the number of points per inch in a given number saw to provide a two-tooth step of movement of the saw. By selecting the appropriate annular row of holes 16 for cooperation with the pin 12 the teeth of a particular number saw can be ground.

In operation a saw [4 to be sharpened, for example, a crosscut saw, is placed in the saw holder or clamp 49 with its row of teeth parallel to the longitudinal axis of the saw holder and with the saw projecting the proper amount from the holder to place the teeth in proper relation to the grinding wheel l2, i. e. in a line passing 1 ations 33.

through the point G. The handle of the saw is accommodated within the recessed halves of the holder 49. The clamping nut 18 is then loosened so that the disk H is free. With the pin 712 in the initial hole of the selected series of holes in the disk and with the first tooth to be sharpened in proper alignment with the grinding wheel l2, the clamping nut is again tightened and the saw has been properly positioned with respect to the series of holes to be used in grinding the teeth.

Also, any desired angular adjustments of the saw with respect to the grinding wheel are made.

In particular, a tooth of the saw can be brought into radial alignment with respect to the grinding wheel by adjustment of the support member 29 on the bracket 26 as indicated by the gradu- The angularity of the face of the tooth with respect to the grinding wheel [2 can be controlled by relative adjustment of the bracket 26 and its arcuate support plate 22. Any desired bevelling of the teeth is effected by adjustment of the mounting plate I! on its support bracket it. It will be recalled that all of these adjustments are related to the point G or" initial engagement of the grinding wheel with respect to the tooth of the saw.

With the above adjustments and settings made.

and the grinding wheel turning, it is brought into engagement with the first tooth of the saw to make the cut and then disengaged. Then the hand wheel 58 is turned to step the pin 12 to the next operative hole of the series which will bring the third tooth into alignment with the grind-. ing wheel 12. This operation is repeated until one-half of the teeth of the saw are sharpened. Thereafter a new adjustment of the saw with respect to the grinding wheel is made with reference to the alternate teeth having the opposite set and the same operation followed through.

In some cases the saw row of holes can be used for different numbered saws where the tooth spacing is, for example, twice as great in one as the other, by skipping alternate holes in a row.

With other types of saws, for example, hand rip saws and hack saws, the desired increment of feed is from tooth to tooth rather than alternate teeth as explained above in connection with crosscut saws. Also, by appropriate modification of the saw holder, the machine will index and sharpen band saw blades for both wood and metal work.

While the description has been made with reference to the sharpening of the teeth of a saw, it will be appreciated that the initial cutting of teeth in the blade of a saw can be effected as well. Also, a sharpening element may be provided of any desired character, for example, a power operated file, in place of the grinding wheel referred to.

While I have shown and described a preferred ment, support means mounting the clamp for movement relatively thereto and for angular adjustment of the clamp about axes at an angle to each other and intersecting at a center coinciding with the point of engagement of the sharpening element with the saw and for adjustment about a 5 third axis passing "through said point, "and intermeshingjgearing carried bysaid clamp and support means for effecting step-by-step movement of said cla'mp past said sharpening element.

12. In asazw sharpener, a sharpening element, a

clamp for presenting a saw to the sharpening element, "support means mounting the clamp for movement relatively thereto and for angular adjustment of the clamp about axes at an angle to each otheri'and intersecting at a :center coinciding with theipoint of engagement of the sharpening element with the saw, and feed mechanism carried by said support means in driving relation to said clamp for effecting step-by-step movement of sai'dclamp past said'isha'rp'ening element.

, 3. In .a saw sharpener, a 's'hanpening element, a clamp for presenting a saw to the sharpening element, support means mounting the clamp for movement relatively thereto and for substantially universal angular adjustment thereof With respect to a center coinciding with the point of engagement of the sharpening element with the saw, and feed mechanism carried by said support means in driving relation to said clamp for effecting step-by-step movement of said clamp past said sharpening element.

4. In a saw sharpener, a sharpening element, a clamp for presenting a saw to the sharpening element, support means mounting the clamp for movement relatively thereto and for angular adjustment of the clamp about axes at an angle to each other and intersecting ata center coinciding with the point of engagement of the sharpening element with the saw and about an axis passing through said point and said saw, and feed mechanism for eii'ecting step-by-step movement of said clamp past said sharpening element, said feed mechanism including a disk having respective radially spaced series of stations representing feed increments and drive means for said clamp carried by said support means having an element for releasable engagement with the stations of any of said series.

5. In a saw sharpener, a sharpening element, a clamp for presenting a saw to the sharpening element, support means mounting the clamp for movement relatively thereto and for angular adjustment of the clamp about a center coinciding with the point of engagement of the sharpening element with the saw, and feed mechanism carried by said support means in driving relation to said clamp for effecting step-by-step movement of said clamp past said sharpening element, said 6 releasabie engagement with the stations of any of said series.

7. In -a saw sharpener, -asharpening-element,a saw clamp having a rack thereon, support structure for said clamp providing -for linear movement thereof, gearing on said support structure for operating said rack, a rotatable dni-ve member for said gearing, and indexing control *means for --said drive member including an :element mounted coaxially therewith and having a series of index stations thereon, said drive member having means engageable with said stations for controlling step-by step movementof said drive member;

8. In a saw sharpener, a sharpening element,-.a saw clamp having a rack thereon, support structure for said clamp providing for linear movement thereof, gearing on said support structure for operating said rack, a rotatable drive member for said gearing, indexing control means for said drive member including an element having a series of index stations thereon, said drive member having means engageable with said stations for controlling step-by-step movement of said drive member, and releasable mounting structure for said element providing for initial adjustment thereof to relate said index stations to the position of a saw in said saw clamp.

9. In a saw sharpener, a sharpening element, a saw clamp having a rack thereon, support structure for said clamp providing for linear movement thereof, gearing on said support structure for operating said rack, a rotatable drive member for said gearing, and indexing control mean:- for said drive member including an element hav ing a plurality of radially spaced arcuate series of index stations thereon, said drive member having radially adjustable means engageable selectively with the stations of said series for controlling step-by-step movement of said drive member.

10. In a saw sharpener, a frame, a sharpening element mounted on said frame, a bracket feed mechanism including a disk having respec- I tive radially spaced series of stations representing feed increments and drive means carried by said support means and geared to said clamp having an element for releasable engagement with the stations of any of said series.

6. In a saw sharpener, a sharpening element, a

' clamp for presenting a saw to the sharpening element, support means mounting the clamp for movement relatively thereto and for adjustment of the clamp with respect to the sharpening element with the saw in two directions at right angles to each other and about an axis passing through said point and said saw, and feed mechanism for effecting step-by-step movement of said clamp past said sharpening element, said feed mechanism including a disk having respective radially spaced series of stations representing feed increments and drive means carried by said support means and geared to said clamp mounted coaxially of said disk and having an element for mounted on said frame for rotative adjustment about an axis intersecting said element, a mounting element carried by said bracket having a concave arcuate surface facing said sharpening element and having a center of curvature lying on said axis and adjacent said sharpening element, a second mounting element having a convex arcuate surface engaged with said concave surface and also having a concave arcuate surface facing said saw and having said center of curvature, said concave surfaces extending at right angles to each other, a holder structure having a convex surface engaged with said second concave surface and having spaced apart guides, a saw clamp slidably engaged with said guides for supporting a saw with the teeth thereof in a line containing said center, and gearing on said holder in driving relation to said clamp.

11. In a saw sharpener, a frame, sharpening element mounted on said frame, a bracket mounted on said frame for rotative adjustment about an axis intersecting said element, a mounting element carried by said bracket having a concave arcuate surface facing said sharpening element and having a center of curvature lying on said axis and adjacent said sharpening element, a second mounting element having a convex arcuate surface engaged with said concave surface and also having a concave arcuate surface facing said saw and having said center of curvature, said concave surfaces extending at right angles to each other, a holder structure having a convex surface engaged with said second concave surface and having spaced apart guides, a saw clamp slidably engaged with said guides for supporting a saw with the teeth thereof in a line containing said center, gearing on said holder in driving relation to said clamp and indexing means for said clamp operatively associated with said gearing, said indexing means being carried by said holder for bodily adjustment therewith.

JAMES MCEWAN.

REFERENCES CITED The following references are of record in the file of this :patent:

Number 15 Number 8 UNITED STATES PATENTS I Name Date Tucker Mar. 11, 1884 Blackmer July 10, 1888 Anderson et a1 Jan. 11, 1916 Hunt Nov. 5, 1918 Elder Jan. 12, 1937 Shaw Sept. 3, 1940 Hellman Feb. 8, 1944 Pollard Feb. 5, 1946 Lofstrand Nov, 12, 1946 Mall Jan. 18, 1949 FOREIGN PATENTS Country Date Great Britain 1881 

